If there's one thing more surprising than Rolling Stone Keith Richards surviving into his 60s, it's that his bandmate Ronnie Wood has done so, too. After all, this is a man so debauched, so obliterated by drink and drugs, and such an all-round pain in the arse that Richards put a gun to his head and threatened to kill him. And that was before things got really bad. Three years ago the Stones guitarist walked out on his wife Jo, who appeared to be the one stabilising influence in his life, and moved in with a teenage girl, and the drink, the drugs, the mood swings all got worse. Many feared the worst.

Yet today he is 15 months clean, has a sensible girlfriend (still young enough to be his grand-daughter, of course), has released a fine solo album and been nominated as radio personality of the year and best newcomer. What went right?

We're at the studio in central London where he records his weekly radio show for Absolute Classic Rock. He's reminiscing about the 60s when great guitarists were 10 a penny. Who was the best – Page, Clapton, Beck, Hendrix? "Jimi [Hendrix] cos he broke all the rules and was such a natural. But Eric was my mainstay because I was a big fan of him with the Yardbirds and I used to share the same girlfriend with him. I got my first wife Krissy from him. We'd always rib each other, 'Oi, take your hands off my bird.'" Didn't they also both have a relationship with Pattie Boyd? "Yeah. Amazing, the camaraderie. And the girls. There was another girl in Los Angeles called Cathy. I thought she was my girlfriend but I found out after she was seeing just about every other guitar player on the circuit."

At the same time? "Yeah. When I was out of town she'd move on to the next one. But in those days it was a kind of unwritten rule, what's mine is yours." And nobody got upset? "No, nobody looked too far into it." He pauses. "Well, some people looked a bit deeper than they should have done and probably got upset."

Wood has one of the most extensive CVs in rock. He played bass in the Jeff Beck group, guitar in the Faces and the Stones (he might have missed out on the golden age, but has still done 36 years with them), hung out with Hendrix, was chased by Janis Joplin, helped Clapton out of his drug haze and collaborated with everybody from Dylan to Aretha to Bo Diddley. His face is a map of dissolution – cheeks like quarries, deep grooves running from nose to mouth – but he has the same black hair (now flecked with tiny bits of silver) in the same feather cut he's always had. At times he bears a disarming resemblance to Dot Cotton; at others, his energy, enthusiasm and boyish figure make him seem more like a teenager. Today he's wearing skinny girl's jeans (28-inch waist), a leopard-skin top, dinky little waistcoat and black cashmere coat. Ronnie Wood is 63 years old.

With Mick Jagger in 1975. Photograph: Getty Images

We're on the roof garden of the studio and Wood is taking one of his many fag breaks. (Actually, it would be more accurate to talk of non-fag breaks.) His beautiful Brazilian girlfriend Ana Araujo is in her early 30s. "Can I 'ave a cigarette, baby?" she whispers to him. She seems sweet, shy and devoted, talking about how she'd like a baby in her late 30s, how both she and Wood are Gemini and have "double balance".

As Wood has his photo taken, I'm staring at his teeth. How come they are so white? "I had them done a few years ago; they trimmed the actual teeth down a bit and put these veneers on top." By rights they should be nicotine-stained and smack-ravaged? He grins. "Yeah, I said I want the veneer to be white and they said, 'Oh, it's not Ronnie Wood to have bloody Hollywood teeth. So we got a built-in stain." He gives me a guided tour of his gob. "A couple of these have fallen out. I got the superglue out. Luckily, last time this one fell out Ana had some glue in her cupboard." She glued them back in with superglue?

"I don't think we want to talk about that in the article," his manager Sherry Daly says.

"Nah, it was dental glue," Wood says. "Keith did it with superglue once. It's a good stand-by."

What about those concave cheeks – are they natural or drug-induced? "I got them from sebaceous cysts while using heroin." He's grinning again. "Amazing the poisons I used to put in my body. I used to love it." His lean figure is, he says, from "drugs, drink, malnutrition. In the States we went past a store in the old days and it said 'discount food' and me and my mate both went, 'Yeah, discount food all together.'"

Why, was there no time? "No time and no inclination, really. I used to have a big breakfast, then sail through the rest of the day. The hole that the drink didn't fill, the cigarettes would." He looks back on those years with pleasure and exhaustion.

"With the youth we could take on anything and conquer it." Sometimes, he says, he still feels like that, but then he remembers the dodgy ankle or ropey shoulder. It's incredible how well he looks, all things considered. He nods. "I'm lucky to be alive because a lot of them have dropped by the wayside, even young people – my kids' friends are dying because they don't know where to stop. And there's a lot of bad drugs around, lots of depression and lots of misuse of alcohol."

People are taking worse drugs now? "Yeah, I think they were purer in our day. And also, it ran in my family to have such resistance to alcohol because my mum and dad, grandparents, brothers, they were on the barges and reared on alcohol." His parents, he has said, were the first generation in his family to live on land. His dad played piano and harmonica, busked and entertained in the music halls. "At my first wedding, Keith [Richards] told me, 'Your dad's got more talent in his little finger than you'll ever have' and I went, 'That's a compliment, even though you're trying to put me down, Keith, because you love my dad.' Archie. Good old Archie…"

While he credits his ox-like constitution to his Gypsy background, drink was partly responsible for prematurely seeing off his two brothers. "Lots of the family lived to a ripe old age, but my brothers went in their 60s. My brother Ted was my age when he went and I don't feel like going. But Ted had given up the will to be ambitious. I'd say, 'Come on, Ted'…" He trails off.

We're back in the studio, the show now finished. Wood has been DJ-ing for only a year, but he is extraordinarily good – relaxed, funny, with a fund of outrageous stories. It's quickly apparent how much he loves the music – he closes his eyes tight, clicks his fingers, dances along, talks over the songs in a rush of giddy enthusiasm. He says he wishes his family could be here to see him. "I think my parents and brothers would have been so proud to see me sober and getting my life back together."

He was 14 when he started drinking heavily – brandy and whisky. In the 70s he drank himself silly because, despite his apparent insouciance, he says he felt insecure in the Faces. At the end of the 70s he started freebasing cocaine – an early form of crack. And, as he says in his autobiography, that was him done for the next five years. It was during this period that Richards threatened to blow his brains out. "When he thinks you're out of control, you think, Christ, there must be something wrong."

In 1985, he married his second wife, Jo, and though she was a moderating influence, he still drank. Until 2003, he claimed he had never played a gig sober. In 2008, he left Jo for Russian model Ekaterina Ivanova. The collapse of his marriage could not have been more public or dramatic. Two days after his daughter Leah's wedding, he ran away with Ekaterina, or Katia as she's also known. His four children were devastated. The 18 months that followed made the previous 50 seem positively abstemious. In December 2009, he was arrested after witnesses alleged he had tried to throttle Katia during a drunken row in the street. Although she didn't press charges, that was the end of their relationship. A few weeks later, he was in rehab for the eighth and, he hopes, final time.

The day before he went into the Priory, Sherry, who has worked with him for 30 years, told him she couldn't cope any more. "I saw her in tears and she said, 'I can't work with you.'" It was an ultimatum?

"No, I made an intervention," she says.

"She gave me love and a tear. [Faces drummer] Kenney Jones was there as well and he said, 'Ronnie, I agree with Sherry' and I thought, 'Fuckin' hell, I must be doing something wrong to affect people like this.' They were in tears."

Many didn't expect him to stick it out. "Lots of people went, 'Oh, give him a couple of weeks and he'll be back on it.' There were a lot of doubting Thomases, and there was something inside me that thought, 'I've got to do this and prove them wrong.'"

Is it true he was "kidnapped" by snooker player Ronnie O'Sullivan and artist Damien Hirst? Yes, he says, sort of, but they did ask him first. "They went, 'Ronnie, d'you want us to come over and help you?' And I went, 'Pleeeeease' cos I couldn't stand myself, I'd just have more and more and more. A bit like I am with the cigarettes now."

If he wasn't in a bar, he'd be drinking alone at home. "I was even worse on my own, because I wouldn't have to face me."

Since he got clean, Wood has enjoyed a sustained creative splurge – painting (he once sold a work for $1m, and says he could make more from his art now than the Stones), a new album and the radio show. Wood is particularly pleased with the solo album, I Feel Like Playing. Over the decades he has released seven albums and written many songs (notably with Rod Stewart on the singer's massive 1972 album Never A Dull Moment, and the title track to the Faces album Ooh La La!). Even so, until now, he has been regarded as a wannabe – the Stones rarely record his songs, and he has said the Jagger/Richards songwriting partnership feels like a bit of a closed shop. But the recent album is a real breakthrough – his voice is more mature and controlled, and there are a few really great songs. Why You Wanna Go And Do A Thing Like That, co-written with Kris Kristofferson, has the makings of a classic. "Even Rod came down to some of the sessions in LA and said, 'Ron, you are now crowned a proper vocalist.' He said, 'I can't believe your improvement.' And Bobby Womack said, 'Ronnie, you're choosing the keys for your songs, you're experimenting' – cos I used to be like a bull in a china shop, I've got an idea and I'm going to sing it: waaaahhhhh!"

With Rod Stewart in 1973. Photograph: Rex

Is the album autobiographical? Of course, he says – what isn't? "A lot of the songs are about the relationship I was in at the time. With Katia. I was leaving home, and walking out of my marriage with Jo. It was something I had to do. I don't know what drove me to it, but I had to do it." He shows me a silver leaf round his neck. "Eric Clapton gave me this freedom leaf. And that's what I wanted, what I felt: I've got to be free of the ties I've got at the moment." Strangely, his daughter Leah also gave him a freedom leaf: "Even though she didn't actually know what was going down at the time. I gave her away, and two days later I was gone."

I had assumed the album looked back with some regret at the relationship with Katia. "No, it was about me having the choice and freedom to be me. Kat would say, 'Why d'you want to go and do a thing like that for, you know, leave home?' And I'm going, 'Yes, it is ridiculous, but let's write a song about it,' so I did."

In a way, he says, he had to completely lose it before recovering his sanity. Many people expected him to run back to Jo and beg forgiveness. Did he? "No, I didn't. A lot of people were going, 'You've fucked up, you've made the worst move of your life', but I was thinking, 'There's something here I've got to discover, and that something is me.' And that was very exciting because I'm much crazier and much more creative when I'm sober."

He admits there's been plenty of pain. His relationship with his children broke down; they were furious with him when he walked out. "I've had my differences with them," he admits with rare understatement. But they've forgiven him now? "Yeah. I used to worry, 'I've lost my family.' They hated my for a while, but they're very resilient. The oldest is 36, the youngest is 28. So they're all grown and they've seen me come through and now they say, 'OK Dad, we love you, we're on your side.'"

After moving out of the Esher home he shared with Jo, Wood went to live in Surrey with Katia. Now he lives alone in a Hoxton studio. He and Jo have split everything down the middle and will continue to do so, he says.

Wood has famously lost tens of millions of pounds over the years – on wine and women, being a useless businessman and just not caring. Now he's convinced those days are over. "Looking at the bills on tour when I was using, I'd have the top wines – I should have been a sommelier because I'm a wine expert and I go from the gutter to the throne in my taste in alcohol." What's the most he'd spend on a bottle? "A thousand pounds… it didn't matter." Has he ever tried to work out how much he's spent on drink and drugs? "No, I haven't, because it's bottomless and it's pointless to go, 'Agh.' It would make me laugh, actually. What, £20m?"

Now, he says, he's so alert to everything, and has so many projects on the go, he doesn't know how to squeeze everything in. What about the Stones? "They're evolving, all doing their own stuff. Charlie's got his jazz band, he's doing his solo stuff, Keith is contemplating his navel and playing with different people and reading, Mick is doing shit, but we want to work together again. When that comes, I don't know."

For the first 17 years of his Stones life he was just a hired hand. Did it make him insecure? "I just looked at it like I was doing my apprenticeship, even though I might have been 50 years old. I was learning, but I was teaching as well: how to let go and enjoy life." He also performed another valuable function – as a glue in the combustible relationship between Jagger and Richards. "During the Dirty Work days, that was a really bad time, I got them through that. I'd be like, 'You stay near the phone, I'm going to get him on the phone and I'll ring you back.'"

Does it feel different now he's a fully fledged member of the band? "That's right, now they listen to me before they make a decision. In the old days, me and Sherry used to say, 'The meek shall inherit the earth, if it's all right with everyone else', but now it's not like that."

Ana walks into the room. He is delighted to see her and gives her a playful slap on the thigh. You seem happy together, I say. "She's part of my adventure and I'm part of hers, cos she gave up… she used to drink a glass of wine and enjoy it, but she said, 'If you need the support, I won't do it' and she hasn't weakened, which I think is very admirable." Is she making him more sensible? "No, but it is nice to be with somebody who isn't like, 'Come on, let's go and get wrecked.' I can go into bars and parties, and I used to feel, 'Euch, I'm really missing out here' but now I don't feel I am – been there, done it."

Despite being divorced from Jo, he is still wearing their wedding ring. "I wear it on my right hand now. She saw it a couple of weeks ago and said, 'You've still got your wedding ring' and I said, 'Yeah, because you're my old mate and you always will be' and she said, 'Yeah, you're my best friend and you always will be.'"

With new girlfriend Ana Araujo. "It it is nice to be with somebody who isn't like, 'Come on, let's go and get wrecked." Photograph: Rex

It's early evening, and he's hungry – another change – so we leave the studio. He's arm in arm with Ana, still puffing away on a fag. He's just made a jingle asking listeners to vote for him in the radio awards. He'd love to win, and thinks it's amazing that he's been nominated. It makes him laugh that, at 63, he's up for best newcomer, but at the same time he thinks there's something weirdly apposite about it. After all, he says, he is just starting out.

•Ronnie Wood is nominated for Music Radio Personality Of The Year and the Sony DAB Rising Star Award at the 2011 Sony Radio Academy Awards. For more information and to cast your vote, go to risingstar.sony.co.uk.